An SISL Dual-Polarized Broadband High-Gain Antenna for Millimeter Wave Applications

A differential-fed dual-polarized antenna based on substrate-integrated suspended line technology is proposed for millimeter-wave base stations. The proposed antenna design is based on all low-cost FR4 substrate layers with embedded air cavities for self-encapsulation. A differential feeding structure is used to improve port isolation and cross-polarization discrimination (XPD). The combination of a cross-shaped structure and slots excites different modes to achieve a wide bandwidth. The gain is further enhanced by stacking patches. The simulated results indicate that the maximum gain from 21.6 to 31.4 GHz is 13.3 dBi. Port isolation is better than 40 dB, and XPD is better than 35 dB. The proposed antenna has the advantages of low cost, wide bandwidth, high realized gain, good cross-polarization resolution, and high port isolation.